Electrical connecting device having insulation penetrating means contacting the conductor



T. T. BUNCH 2,724,809 ELECTRICAL CONNECTING DEVICE HAVING INSULATION Nov. 22, 1955 PENETRATING MEANS CONTACTING THE CONDUCTOR Filed Dec. 11, 1955 35 FIG. I

//V l/E N TOR f. 7f BUNCH By .4 T TORNEV FIG. 2

United Sttes Patent ELECTRICAL CONNECTING DEVICE HAVING INSULATION PENETRATENG MEANS CON- TACTING THE CONDUCTOR Tillman T. Bunch, near Ashland, Md, assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application December 11, 1953, Serial No. 397,537

4 Claims. (Cl. 339-97) This invention relates to electrical connecting devices, and more particularly to a grounding terminal and clamp for plastic insulated wire.

This application is a division of my copending application Serial No. 248,327, filed September 26, 1951, for Apparatus for Coiling Filamentary Articles, now Patent 2,709,051, granted May 24, 1955.

In the past, considerable difliculty has been encountered in providing suitable apparatus for quickly connecting a plastic insulated, multiconductor wire both mechanically and electrically. It has been found that conventional apparatus cannot be used to make such connections on multiconductor wires of the type in which the conductors are not coplanarly arranged without the risk of severing one or more of the conductors of the wire.

It is an object of this invention to provide new and improved electrical connecting devices.

It is another object of this invention to provide a new and improved grounding terminal and clamp.

A device embodying certain features of the invention, may include a pair of relatively movable cooperating jaws provided with substantially flat clamping surfaces, and means for moving the jaws into engagement with a plastic insulated conductor positioned therebetween with sufiicient force to cause plastic insulating material surrounding the conductor to be squeezed aside to bare the conductor and cause the jaws to make electrical contacts with the conductor.

A complete understanding of the invention may be had from the following detailed description of an electrical connecting device forming a specific embodiment thereof, when read in conjunction with the appended drawing, in which:

Fig. 1 is a vertical section of a coiling apparatus including an electrical connecting device embodying the invention, with parts thereof broken away for clarity;

Fig. 2 is an enlarged, fragmentary, perspective view of the electrical connecting device, with parts thereof broken away for clarity;

Fig. 3 is an enlarged, fragmentary view of clamping jaws forming a part of the electrical connecting device;

Fig 4 is a fragmentary, vertical section taken along line 44 of Fig. 1, and

Fig. 5 is a fragmentary, vertical section taken along line 5-5 of Fig. 4.

Referring to Fig. 1 of the drawing, there is shown a coiling head including a tubular coiling arbor secured to a flanged end 11 of a hollow, rotatable drive shaft 14. The coiling arbor 10 is designed to receive a plurality of nested coiling sections 16, 17 and 18 which are detachably connected to each other and an annular backing plate 20 by means of cooperating interlocking tongues and slots provided thereon. The backing plate 20 is secured to a flanged ring which is fixedly mounted on the coiling arbor 10 for rotation therewith. A springbiased latching mechanism, indicated generally at 27, is provided for urging the nested coiling sections 16, 17

2,724,809 Patented Nov. 22, 1955 ice and 18 together against the backing plate 20 for rotation with the arbor 10.

Referring again to Fig. 1, there is shown an improved grounding clamp 35 for rapidly connecting to ground one end of a multiconductor wire 37 to be wound upon the sections of the coiling head. The clamp 35 includes a pair of spaced mounting brackets, one of which designated 40 is shown in Fig. 1, mounted fixedly to the rear face of the flanged ring 25. Mounted between the lower ends of the brackets 40-40 is a block 41 provided with a longitudinally extending bore 42 having at one end a bell-mouthed entrance 44. The lower portion of the block 41 is cut away adjacent to the opposite end of the bore 42 and supports a stationary lower jaw 46, which is fixedly secured thereto by fasteners 4747. The upper portion of the block 41 which overhangs the stationary lower jaw 46, is provided with a circular aperture 48 oriented perpendicularly with respect to the longitudinal axis of the bore 42. Slidably received in the aperture 48; is a reciprocable upper jaw 49 designed to cooperate with the stationary lower jaw 46.

The upper jaw 49 is provided with an elongated rodlike extension 50, the upper end of which is received slidably within aligned apertures 51 and 52 in the arbor 10 and flanged ring 25, respectively. A forked arm 55 of a bell crank 56, pivotally mounted between the brackets 4040 on a shaft 57, is operatively connected to the rod-like extension 59 of the upper jaw 49 by virtue of being retained between threaded adjustment nuts 60 and 61. The nuts 60 and 61 are threadedly engaged on a threaded intermediate portion of the rod-like extension 50 and are spacedly adjustable to facilitate compensatory adjustments in the predetermined separation of the jaws 46 and 49 when the jaws are urged together to clamp the end of the wire 37 therebetween. Another arm 63 of the bell crank 56 extends through a longitudinal slot 65 formed in the bottom of the arbor 10. A rounded extremity of the arm 63 is received within a socket 63 formed in a cylindrical sleeve which is slidably mounted for reciprocation within the tubular arbor 10.

The sleeve 70 is operatively connected to the left end of an axially movable push rod 72 which is mounted coaxially and slidably within the drive shaft 14 and extends partially into the tubular arbor 10. The left end of the push rod 72 is threaded and extends through a central aperture 74 in a disk 76 fixedly secured to the left end of the sleeve '70. The disk 76 is retained on the push rod 72 by means of an adjustable threaded nut 77. The push rod 72, disk 76 and attached sleeve 70 are urged normally to the left, as viewed in Fig. 1, by a compression spring 79 mounted in the arbor 10 between the disk and the flanged end 11 of the shaft 14. The adjustable nut 77 mounted on the threaded end of the push rod 72, permits adjustments in the amount of force norinally exerted by the spring 79.

As may be seen in Fig. 1, when the sleeve 70 is urged normally to the left, it in turn urges the bell crank 56 counterclockwise to urge the upper jaw 49 toward the lower jaw 46. The push rod 72 is operated by means of a foot pedal 81 which is connected to the push rod through a series of linkages 82 and 83. When the foot pedal 81 is depressed, it urges the sleeve to the right against the action of the spring 7, thereby causing the bell crank 56 to rotate clockwise to move the jaws 46 and 49 apart.

The wire 37 (Fig. 3) comprises three conductors 8585 covered with plastic insulating sheaths 8787p The conductors 85-85 Cooperating clamping surfaces 92') and 92 (Fig. 5) of the jaws 46 and 49, respectively, are substantially flat, except for relatively small chisel-like teeth 9-? and 95. The teeth 94 and 95 are mounted in opposition on the jaws 46 and 49, respectively, and are oriented perpendicularly with respect to the bore 42. By design the height of each of the teeth 94 and 95 is made substantially less than the normal uncompressed, combined thicknesses of the insulating sheath 87 and jacket 39 separating a conductor 85 from the outer periphery of the jacket.

Operation Preparatory to a coiling operation, two empty coiling sections 16 and 17 are positioned on the arbor it The tongues of the innermost section 16 adjacent to the back ing plate 20 are inserted in the corresponding slots formed in the backing plate and the tongues of the other section 17 are inserted in the slots formed in the section 16. The outer coiling section it. is then mounted and held flush against the end of the arbor iii by the wedging action of the latching mechanism 27 with the tongues of the outer section received within corresponding slots in the adjacent coiling section 17.

An operator next inserts the leading end of the multiconductor wire 37 through the bore in the block 41 after first depressing the foot pedal 81 to separate the jaws 46 and 49 of the clamp 35. With the leading end of the wire 37 positioned between the jaws 46 and 49, the operator then releases the foot pedal 81, whereupon the compression spring 79 urges the sleeve '79 to the extreme left, as viewed in Fig. l, to urge the bell crank 56 rotatably in a counterclockwise direction. The counterclockwise movement of the bell crank 56 urges the movable upper jaw 49 downwardly toward the stationary lower jaw 46.

As the jaw 49 moves downwardly toward the jaw 46 under the force of the spring, the cooperating fiat clamping surfaces 91 and 92 of the jaws 46 and 49, respectively, engage the wire 37. The cooperating flat clamping surfaces 91 and 92 of the jaws 46 and 49 initially force the conductors 525-85, which were previously in a standard equilateral spacial arrangement (Fig. 3), into a coplanar arrangement, shown in Fig. 4, at the impact region, simultaneously reducing the thickness of the insulating coverings 87-87 and jacket 89 separating the conductors 8585 from the jaws 46 and 49. This deforming action, wherein the conductors d5-35 are forced into a coplanar arrangement, occurs before the teeth 94 and 95 engage the conductors, since the height of each of the teeth is substantially less than the uncompressed, combined thicknesses of the insulating coverings 87-87 and jacket 39 and prevents the conductors from being severed. After the conductors 85t5 have assumed a coplanar relationship, the continued movement of jaws 46 and 49 under the influence of the force exerted by the spring 79 crushes the insulating coverings 8787 and jacket 89 to a thickness slightly less than the height of the teeth 94 and 95, whereby the teeth simultaneously engage all three conductors.

Throughout the subsequent coiling operation, during which the wire 37 is wound upon the coiling sections 16, 17 and 18 of the coiling head, the jaws i6 and 49 are maintained in engagement with the leading end of the wire with their teeth 94 and 95 mechanically and electrically connected to all three of the conductors. At the finish of the coiling operation, this connection is disestablished by depressing the foot pedal 81 to separate the jaws 46 and 49 and by removing the leading end of the wire 37 from the bore 42.

The separation of the jaws 4'5 and 49 when closed may be adjusted by selectively positioning the adjustable nuts 60 and 61 on the threaded portion of the extension 50. In addition, the force exerted on the jaw 49 by the bell a; crank 536 may be adjusted by means of the adjustment nut 77 on the threaded end of the push rod 72.

It will be understood that the use of the teeth 94 and 95 on the jaws 46 and 49, respectively, of the clamp is optional. if sufficient force is applied by the spring 79 to the bell crank 56 to urge the jaws 46 and 49 together, it is unnecessary to provide the jaws with teeth. The flat clamping surfaces 91 and 92 on the jaws 46 and 49, if urged together with sufficient force, will crush the insulating coverings 87-87 and jacket 89 and cause them to be squeezed completely from therebetween, thereby exposing the conductors -35, which have been previously forced into a coplanar arrangement, to establish an electrical grounding contact between the jaws and the bared conductors.

it is manifest that various modifications of the abovedescribed device may be made within the spirit and scope of the invention.

What is claimed is:

l. A combined terminal and clamp for plastic insulated multiconductor wire including a plurality of equilaterally spaced, filamentary conductors which are separated from the outer periphery of the wire by substantially equal predetermined thicknesses of plastic insulating material,

which comprises a pair of relatively movable jaws provided with substantially fiat, parallel, cooperating clamping surfaces, a pair of opposed chisel-like teeth, a tooth being provided on the flat clamping surface of each of said jaws and having a height substantially less than the normal, uncompressed thickness of plastic insulating material separating a conductor from the periphery of the wire, and means for urging the jaws together to engage a wire positioned therebetween with a force sufficient to cause the several conductors of the wire to assume a coplanar arrangement and the plastic insulating material to be squeezed aside to permit the teeth to electrically contact the conductors simultaneously.

2. A combined terminal and clamp for plastic insulated multiconductor wire including a plurality of equilaterally spaced, filamentary conductors which are separated from the outer periphery of the wire by substantially equal predetermined thicknesses of plastic insulating material, which comprises a block provided with a passageway extending therethrough, a stationary jaw mounted adjacent to the exit end of the passageway and provided with a substantially fiat clamping surface, a movable jaw mounted slidably on the block and provided with a substantially fiat clamping surface disposed in parallel relationship with respect to the clamping surface on the stationary jaw, a pair of opposed chisel-like teeth, a tooth being provided on the flat clamping surface of each of said jaws and having a height substantially less than the normal, uncompressed thickness of plastic insulating material separating a conductor from the periphery of the wire, and means for urging the jaws together to engage such a wire positioned therebetween with a force sufficient to cause the several conductors of the wire to assume a coplanar arrangement and the plastic insulating material to be squeezed aside to the extent that the teeth electrically contact all of the conductors.

3. A combined terminal and clamp for plastic insulated multiconductor wire including a plurality of equilaterally spaced, filamentary conductors which are separated from the outer periphery of the wire by substantially equal predetermined thicknesses of plastic insulating material, which comprises a pair of relatively movable cooperating jaws provided with substantially fiat, parallel, cooperating clamping surfaces, means for forcing the movable jaws toward each other into engagement with such a plastic insulated multiconductor wire with a force sufficient to cause the several conductors of the wire to assume a coplanar arrangement and the plastic insulating material to be squeezed aside, whereby said conductors are bared to allow the jaws to make electrical contacts therewith,

and means for maintaining a predetermined minimum separation between the jaws when said jaws are in their most contiguous position.

4. A combined terminal and clamp for plastic insulated multiconductor wire including a plurality of equilaterally spaced, filamentary conductors which are separated from the outer periphery of the wire by substantially equal predetermined thicknesses of plastic insulating material, which comprises a block provided with a longitudinally extending bore, a stationary jaw mounted adjacent to the exit end of said bore, a movable jaw mounted slidably on the block for cooperation with said stationary jaw to clamp an insulated conductor positioned in the bore therebetween, each of said jaws being provided with sub stantially flat, parallel, cooperating clamping surfaces, means for forcing the movable jaws toward each other into engagement with such a plastic insulated multiconductor wire with a force sufficient to cause the several conductors of the wire to assume a coplanar arrangement and the plastic insulating material can be squeezed aside, whereby said conductors are bared to allow the clamping surfaces on the jaws to make electrical contacts therewith, and means for maintaining a predetermined minimum separation between the clamping surfaces of the jaws when said clamping surfaces are in their most contiguous position.

References Cited in the file of this patent UNITED STATES PATENTS 1,275,336 Weatherill Aug. 13, 1918 2,196,964 Lee Apr. 9, 1946 2,624,771 Hanson Jan. 6, 1953 

